As shown in FIG. 1, the conventional keyswitch 1 for notebook computer at least comprises a substrate 10, a flexible circuit layer 11, a resilient dome 12, a supporting lever 13 and a keytop 14. The substrate 10 is provided with a first retaining hook 100, a second retaining hook 101, a first through hole 102 and a second through hole 103. The flexible circuit layer 11 and the resilient dome 12 are respectively stacked on the substrate 10. The supporting lever 13 comprises a first lever 130 and a second lever 131 pivotal to each other in scissors arrangement. The first lever 130 comprises a rounded sliding shaft 132 on bottom side thereof and slidable within the first retaining hook 100. The top of the first lever 130 is pivotally connected to the keytop 14. The second lever 131 comprises a rounded rotating shaft 133 on bottom side thereof and rotatable within the second retaining hook 101. The top of the second lever 130 is slidably connected to the keytop 14. The keytop 14 can be lowered to strike the resilient dome 12 by the rotating movement of the rotating shaft 133 and the sliding movement of the sliding shaft 132. The resilient dome 12 is collapsed to turn on the corresponding switch on the flexible circuit layer 11 and generate associate keyswitch signal.
However, in above-mentioned keyswitch 1, both the rotating shaft 133 and the sliding shaft 132 lay against the substrate 10 at location beside the though holes 102 and 103, or against the flexible circuit layer 11 upon the substrate 10. Therefore, the first retaining hook 100 and the second retaining hook 101 have abrupt-raising height to accommodate the rotating shaft 133 and the sliding shaft 132. The whole supporting lever 13 is forced to place upon the flexible circuit layer 11 and the height of the keytop 14 relative to the flexible circuit layer 11 can not be reduced. Moreover, the supporting lever 13 is in contact with the flexible circuit layer 11 or the substrate 10 by the tangential portion of the rotating shaft 133 and the sliding shaft 132, the stability of the supporting lever 13 is poor. The supporting lever 13 may shake when the keytop 14 is pressed.
To overcome above problem, an improved structure of keyswitch is provided and comprises a circuit base with a circuit layer, a resilient dome, a supporting lever and a keytop. The circuit base further comprises a substrate and a flexible circuit layer. T supporting lever comprising a first lever and a second lever pivotal to each other in scissors arrangement. The first lever has a sliding portion on bottom side thereof and the second lever has a rotating portion on bottom side thereof and a sliding portion on top side thereof. The sliding portion of the first lever comprises two clamping blocks and a sliding shaft arranged between the two clamping blocks. The clamping block is extended from the sliding shaft such that the edge at the intersection of an outer surface of the sliding shaft and an bottom surface of the sliding shaft is an embowed square shape. The sliding shaft is entirely or partially embedded into the first through hole. The rotational portion of the second lever has two rotational shafts retained between the second retaining bodies and embedded within the second through hole. Therefore, the height of the keyswitch is lowered and the key pressing operation is more stable.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: